[Cfp-interest 2834] Re: CFP review of TS-4 and TS-5 revisions

[Damian McGuckin]

On Sun, 6 Aug 2023, Jim Thomas wrote:

> 6 Reduction functions ? Damian

OK - Here goes:

Section 6:

(Page No 2 which is the 10th page of the Document)

* Line 14-15:

 	Line 15 says:

 		The type declared is size_t.

 	It is not obvious what "the type" is all about.

 	I know that size_t corresponds to the requirement by IEEE 754 for
 	integralFormat to be defined.

 	However, the sentence seems like is it missing but I am not exactly
 	what sure what it is trying to say. Should it be

 		The size_t type is declared within <math.h>??

 	Or maybe that means that the previous sentence (Line 14)
 	needs to be reworded.

 	Sorry, I do not have the answer but Line 14 and 15 seem vague
 	unless you read in at the same time as you read the IEE 754
 	standard. And then it is obvious.

* Line 21:

 	the overflow or underflow floating-point exception is raised and a range
 	error occurs if and only if the determination of the final result overflows
 	or underflows.

 	The phrase

 		determination of the final result

 	implies (to me) the actual process that produces the final result.

 	And the whole idea is to avoid redundant exceptions during that
 	process.

 	Does it mean the same if you use less words and say just:

 		... if and only if the final result overflows or underflows.

 	That is also simpler.

* Line 33:

 	is the word "may" correct or should it be stronger?

6.1: (Page No 3)

* Line 26-27:

 	... Otherwise (if no member of p is a NaN and no two members of p
 	are infinities with different signs), if any member of array p is
 	an infinity, the functions return that same infinity.

 	I would personally omit the command and replace it with 'and'.

 	Or have I changed the meaning.

6.2: (Page No 4)

* Line 23-26

 	This text is not consistent with 6.1.  What were two sentences are
 	now linked into a single sentence with a semi-colon and "otherwise,".
 	But the second half of that sentence is about NaN, the first half is
 	about Infinity. They are strictly unrelated. Why merge them.

 	I suggest keeping the text consistent with 6.1 which also reduces
 	the sentence length.

 	The reduc_sumabs functions compute the sum of the absolute values of
 	the n members of array p: (SIGMA stuff) |p[i]|. If the length n = 0,
 	the functions return the value +0. If any member of array p is an
 	infinity, the functions return INFINITY-symbol; If any member of
 	array p is a NaN, the functions return a quiet NaN.

 	My 2c.

 	(Questionable comment)

 	Why, when we use Mag[nitude] in the max/min function, do we use the
 	abs[solute-value] concept here. This is a sum by magnitudes.

 	Yes, I know that is to match IEEE 754 2019.

6.3: (Page No 5)

* Line 23-26

 	Same comment as for 6.2.

 	The reduc_sumaq functions compute the sum of the squares of
 	the n members of array p: (SIGMA stuff) (p[i]*p[i]). If the length n = 0,
 	the functions return the value +0. If any member of array p is an
 	infinity, the functions return INFINITY-symbol; If any member of
 	array p is a NaN, the functions return a quiet NaN.

6.4: (Page No 6)

* Line 36

 	I suggest replacing the comma with

 		and

 	and removing the parentheses.

6.5: (Page No 7)

# Lines 33-42 - The Description

 	The text goes

 		If ...
 		If ...
 		If ...
 		If ...
 		Otherwise ...
 		Otherwise ...
 		Otherwise ...
 		If ...

 	If that was a program, I would be worried.

 	why use Otherwise? It is not consistent anyway (at least the way
 	I read it). But that is a personal opinion and I am open to
 	change.

6.6: (Page No 8)

* Lines 40-overpage - The Description:

 	Same comment as for 6.5.

6.7: (Page No 9)

* Lines 44-overpage - The Description:

 	Same comment as for 6.5.

Note that something tells me that implementing those to avoid redundant
exceptions is going to be a nightmare. But that is not what we are doing
here.

Thanks - Damian

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